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Diffstat (limited to 'cpu/blackfin/start.S')
| -rw-r--r-- | cpu/blackfin/start.S | 238 |
1 files changed, 0 insertions, 238 deletions
diff --git a/cpu/blackfin/start.S b/cpu/blackfin/start.S deleted file mode 100644 index 7a3abba..0000000 --- a/cpu/blackfin/start.S +++ /dev/null @@ -1,238 +0,0 @@ -/* - * U-boot - start.S Startup file for Blackfin u-boot - * - * Copyright (c) 2005-2008 Analog Devices Inc. - * - * This file is based on head.S - * Copyright (c) 2003 Metrowerks/Motorola - * Copyright (C) 1998 D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>, - * Kenneth Albanowski <kjahds@kjahds.com>, - * The Silver Hammer Group, Ltd. - * (c) 1995, Dionne & Associates - * (c) 1995, DKG Display Tech. - * - * See file CREDITS for list of people who contributed to this - * project. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation; either version 2 of - * the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, - * MA 02110-1301 USA - */ - -#include <config.h> -#include <asm/blackfin.h> -#include <asm/mach-common/bits/core.h> -#include <asm/mach-common/bits/dma.h> -#include <asm/mach-common/bits/pll.h> - -#include "serial.h" - -/* It may seem odd that we make calls to functions even though we haven't - * relocated ourselves yet out of {flash,ram,wherever}. This is OK because - * the "call" instruction in the Blackfin architecture is actually PC - * relative. So we can call functions all we want and not worry about them - * not being relocated yet. - */ - -.text -ENTRY(_start) - - /* Set our initial stack to L1 scratch space */ - sp.l = LO(L1_SRAM_SCRATCH_END - 20); - sp.h = HI(L1_SRAM_SCRATCH_END - 20); - -#ifdef CONFIG_HW_WATCHDOG -# ifndef CONFIG_HW_WATCHDOG_TIMEOUT_START -# define CONFIG_HW_WATCHDOG_TIMEOUT_START 5000 -# endif - /* Program the watchdog with an initial timeout of ~5 seconds. - * That should be long enough to bootstrap ourselves up and - * then the common u-boot code can take over. - */ - P0.L = LO(WDOG_CNT); - P0.H = HI(WDOG_CNT); - R0.L = 0; - R0.H = HI(MSEC_TO_SCLK(CONFIG_HW_WATCHDOG_TIMEOUT_START)); - [P0] = R0; - /* fire up the watchdog - R0.L above needs to be 0x0000 */ - W[P0 + (WDOG_CTL - WDOG_CNT)] = R0; -#endif - - /* Turn on the serial for debugging the init process */ - serial_early_init - serial_early_set_baud - - serial_early_puts("Init Registers"); - - /* Disable self-nested interrupts and enable CYCLES for udelay() */ - R0 = CCEN | 0x30; - SYSCFG = R0; - - /* Zero out registers required by Blackfin ABI. - * http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface - */ - r1 = 0 (x); - /* Disable circular buffers */ - l0 = r1; - l1 = r1; - l2 = r1; - l3 = r1; - /* Disable hardware loops in case we were started by 'go' */ - lc0 = r1; - lc1 = r1; - - /* Save RETX so we can pass it while booting Linux */ - r7 = RETX; - -#if CONFIG_MEM_SIZE - /* Figure out where we are currently executing so that we can decide - * how to best reprogram and relocate things. We'll pass below: - * R4: load address of _start - * R5: current (not load) address of _start - */ - serial_early_puts("Find ourselves"); - - call _get_pc; -.Loffset: - r1.l = .Loffset; - r1.h = .Loffset; - r4.l = _start; - r4.h = _start; - r3 = r1 - r4; - r5 = r0 - r3; - - /* Inform upper layers if we had to do the relocation ourselves. - * This allows us to detect whether we were loaded by 'go 0x1000' - * or by the bootrom from an LDR. "R6" is "loaded_from_ldr". - */ - r6 = 1 (x); - cc = r4 == r5; - if cc jump .Lnorelocate; - r6 = 0 (x); - - /* In bypass mode, we don't have an LDR with an init block - * so we need to explicitly call it ourselves. This will - * reprogram our clocks, memory, and setup our async banks. - */ - serial_early_puts("Program Clocks"); - - /* if we're executing >=0x20000000, then we dont need to dma */ - r3 = 0x0; - r3.h = 0x2000; - cc = r5 < r3 (iu); - if cc jump .Ldma_and_reprogram; -#else - r6 = 1 (x); /* fake loaded_from_ldr = 1 */ -#endif - r0 = 0 (x); /* set bootstruct to NULL */ - call _initcode; - jump .Lprogrammed; - - /* we're sitting in external memory, so dma into L1 and reprogram */ -.Ldma_and_reprogram: - r0.l = LO(L1_INST_SRAM); - r0.h = HI(L1_INST_SRAM); - r1.l = __initcode_lma; - r1.h = __initcode_lma; - r2.l = __initcode_len; - r2.h = __initcode_len; - r1 = r1 - r4; /* convert r1 from load address of initcode ... */ - r1 = r1 + r5; /* ... to current (not load) address of initcode */ - p3 = r0; - call _dma_memcpy_nocache; - r0 = 0 (x); /* set bootstruct to NULL */ - call (p3); - - /* Since we reprogrammed SCLK, we need to update the serial divisor */ -.Lprogrammed: - serial_early_set_baud - -#if CONFIG_MEM_SIZE - /* Relocate from wherever we are (FLASH/RAM/etc...) to the hardcoded - * monitor location in the end of RAM. We know that memcpy() only - * uses registers, so it is safe to call here. Note that this only - * copies to external memory ... we do not start executing out of - * it yet (see "lower to 15" below). - */ - serial_early_puts("Relocate"); - r0 = r4; - r1 = r5; - r2.l = LO(CONFIG_SYS_MONITOR_LEN); - r2.h = HI(CONFIG_SYS_MONITOR_LEN); - call _memcpy_ASM; -#endif - - /* Initialize BSS section ... we know that memset() does not - * use the BSS, so it is safe to call here. The bootrom LDR - * takes care of clearing things for us. - */ - serial_early_puts("Zero BSS"); - r0.l = __bss_vma; - r0.h = __bss_vma; - r1 = 0 (x); - r2.l = __bss_len; - r2.h = __bss_len; - call _memset; - -.Lnorelocate: - - /* Setup the actual stack in external memory */ - sp.h = HI(CONFIG_STACKBASE); - sp.l = LO(CONFIG_STACKBASE); - fp = sp; - - /* Now lower ourselves from the highest interrupt level to - * the lowest. We do this by masking all interrupts but 15, - * setting the 15 handler to ".Lenable_nested", raising the 15 - * interrupt, and then returning from the highest interrupt - * level to the dummy "jump" until the interrupt controller - * services the pending 15 interrupt. If executing out of - * flash, these steps also changes the code flow from flash - * to external memory. - */ - serial_early_puts("Lower to 15"); - r0 = r7; - r1 = r6; - p0.l = LO(EVT15); - p0.h = HI(EVT15); - p1.l = .Lenable_nested; - p1.h = .Lenable_nested; - [p0] = p1; - r7 = EVT_IVG15 (z); - sti r7; - raise 15; - p4.l = .LWAIT_HERE; - p4.h = .LWAIT_HERE; - reti = p4; - rti; - - /* Enable nested interrupts before continuing with cpu init */ -.Lenable_nested: - cli r7; - [--sp] = reti; - jump.l _cpu_init_f; - -.LWAIT_HERE: - jump .LWAIT_HERE; -ENDPROC(_start) - -LENTRY(_get_pc) - r0 = rets; -#if ANOMALY_05000371 - NOP; - NOP; - NOP; -#endif - rts; -ENDPROC(_get_pc) |